This invention relates to a simplified protective helmet for use in military or other applications requiring protection of the head against ballistic impacts.
Our application entitled "Improved Protective Helmet," Ser. No. 500,547, filed Aug. 26, 1974, now Pat. No. 3,897,596, discloses a protective helmet of the type in which a headband assembly, chin strap assembly and crown assembly supporting frame molded of relatively rigid plastic material is provided with a peripheral channel for receiving the edge of a hard ballistic outer shell retained in assembled relationship with the frame by use of only a single fastener. A shoulder located inwardly of the peripheral channel is provided with a plurality of inwardly spaced upwardly and slightly inwardly directed fingers and with holes and channels which receive a cord by means of which the headband assembly and the chin strap are held in place. In the assembly shown in our co-pending application, envelopes formed of glove leather or the like receive soft spacer bodies which are slipped over the fingers and which are secured to the frame by means of snap fasteners carried by the flaps on the envelopes and by the frame to cooperate with the fingers to form the headband of the assembly. Each of the crown assembly straps includes a permanent loop at one end, which is received by a portion of the cord on the outside of the frame shoulder, and an adjustable loop at the other end thereof, which is received by another portion of the cord on the outside of the shoulder.
While the improved protective helmet of our co-pending application successfully achieves the result of providing a ballistic helmet which is capable of mass production at relatively low cost, while at the same time avoiding the danger of injury to the head of the wearer as a result of fastener elements and the like in the hard outer shell, which may act as secondary missiles, it is not as convenient in use as is desired. First, it does not permit the crown straps to be adjusted without removing the frame from the hard ballistic outer shell. Secondly, the assembly of the envelopes and pads on the resilient fingers is relatively cumbersome in use. Not only does the assembly not accommodate as wide a range of head sizes as is desirable, but also adjustment of head sizes is relatively difficult.